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RR503

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Posts posted by RR503

  1. 1 hour ago, Union Tpke said:

    @RR503 Does your map have an (R) West End express?

    That's something I forgot to add/would definitely do. 

    1 hour ago, JeremiahC99 said:

    For the second map, what I would've done was to have the (N) move to 96th Street with the (Q), with the (W) getting a service boost to 12 trains per hour (your map depicts broadway mostly remaining the same). The (R) would remain mostly unaffected, though it would have one less merge to deal with. This would allow for more frequent service on the SAS, and more reliable local service. 

    Issue is capacity along Broadway. You need the full 15tph for loads in Astoria, and you can't go above 21tph at City Hall Curve. The math there just doesn't work -- 6tph to/from Queens Blvd just won't cut it. If that constraint didn't exist, that's absolutely what I'd do. 

    1 hour ago, JeremiahC99 said:

    For map number 3, 59th Street is depicted as serving the (N)(R), but the (R) is already on West End. Shouldn't it be (N)(Q) since the (Q) is going to 95th Street? In addition, I would also keep the mixing of trains at 145th Street that you feature on Map 2. Since the (A)(C) are the 8th Avenue express and the (B)(D) are 8th Avenue local, it would make some sense to have one of each on both northern end, that way no one loses their express service, and the passengers in Washington Heights and the Bronx have access to both 8th Avenue and 6th Avenue again, all while deinterlining 59th Street. That's just my take. I also would've recommended a rebuild of 149th Street-Concourse junction since the current (5) service over there is still popular. That's just my take on it.

    Good catch. Will fix. 

    I deinterlined 149 because the current merges there are just...so...bad. I'm sure I've posted the chart before, but if not:

    xQl83xZ.png

    Despite the (4) bypassing 138 at rushes, runtimes are almost double what they are off peak. That's 100% merge congestion, and it's congestion that really isn't doing any good for Lex. You're right that it'd be an unpopular move, but honestly with runtimes that nuts, it may actually work out to a net positive in total trip time. 

    The logic at 145 builds off of this: with 30tph of capacity going up Jerome and greater capacity along Lex, there's less of an incentive to have Concourse operating as an interlined relief route. That's why I undid 145, though it isn't a decision I'd be all that unhappy about reversing -- 145 is a crap merge, but thanks to its design it generally doesn't create cascading impacts. 

  2. 3 minutes ago, Union Tpke said:

    @RR503 Why do you elect to improve Burnside over Bedford Park Boulevard? Doing that along with grade-separating the yard leads could allow for express service.

    It would, and in a perfect world I'd do just that. But I was trying to keep the list of things there to things I could actually see happening, so Burnside switches it is! 

    (Also, demand growth in the Bronx is concentrated in the southern portion of the borough. Don't know if we necessarily want to be running 30tph+ that far north)

  3. 6 minutes ago, Union Tpke said:

    Great maps! I find it interesting that you elected to extend the (R) to 179th Street in that map to relieve pressure off of Continental. Why extend the (R) over the (M)?

    I'd prefer to see the (M) given that the (R) is already a bit of a mess, but given the blowback experienced on a certain pilot because we were replacing 10 cars with 8, I figured that may be a price worth paying. It's not a decision I have any strong feelings about, though. 

    1 minute ago, LaGuardia Link N Tra said:

    I guess, but the (N) and (W) share the same fleet. So I don’t see how Yard Access would be a problem. Besides, the crews can always switch the signage between the (N) and (W) at Ditmars Blvd. Not sure if they still do that given the recent fleet swap.  

    You could work it like that, but there's also a capacity problem. Both the (N) and (R) run 10tph peak into Manhattan from Brooklyn -- you can't merge those both into Astoria with current terminal infrastructure. You could run more 96 St (N)s, but then it becomes harder to manage yards. There's a similar issue with Queens, the (R)'s 10tph can't all turn at Whitehall, so you're either stuck with an ugly mainline discharge at Canal or an extension to Brooklyn, at which point we're basically back where we're started. The nice thing about the (W) is it's a low frequency overlay that's easily adjustable into capacity gaps. I think it's best we keep it that way, and if we're really worried about the (R)'s length, extend the (M) instead.

  4. Just now, Union Tpke said:

    I agree with you about DeKalb. Earlier on you had posted that you would prefer that operational fixes be made, and then if those failed, then do deinterlining. What finally pushed you to believe in deinterlining there? Do you think any upgrades would be needed at Atlantic Avenue. A transfer should be built between Broadway-Lafayette and Prince Street.

    Knowing more. I've done a lot of work with that area and with those lines, and the more you get into it the more you realize just how impossibly difficult it is to run a reliable and frequent railroad with merges like Dekalb. This isn't to say we shouldn't go for things like eliminating the CCTV stop, better signing area STs and the like -- if for no other reason than I have about 0% confidence of Dekalb deinterlining going forwards anytime soon -- but there's just no way to run a system used by humans precisely enough that you can make a 30 second wide merge window.

  5. This is really gonna require federal assistance to fix. Through fares and its collection of economically sensitive taxes, MTA is very exposed to economic fluctuations in its operating budget, and the state already has plenty on it's budgetary plate. I'm really hoping congress/FTA pulls through with a sizable temporary operating assistance program for transit agencies in general, but I've been doing this long enough to know not to hold my breath. 

  6. Now, for some fun. I finally made maps of my various deinterlining ideas. 

    Today's service 

    https://drive.google.com/open?id=1HHNa2XqlrDKPIKUzpTJcyQbSndtbs1cM

    What I'd do without spending any capital $$$

    https://drive.google.com/open?id=1yZcwJfjcO1tfYuttqW2lUuatAFvIaxuz

    What I'd do with capital $$$

    https://drive.google.com/open?id=15z4fvc1cfxxtY_ZhUbFex3jxgT0dt3lm

    The general principles here are to minimize merges/maximize capacity while trying to preserve a maximum of important connectivity (so we deinterline CPW, but not Essex or Bergen), and on the no-$$$ map to try to jump for deinterlinings that can largely be achieved through low-effort swaps, ie (D)(Q), (F)(M), (C)(D). Nothing on here will be all that unfamiliar to those of you who've been reading my ramblings for a while, but I thought it'd be nice to see it all on one map. 

  7. On 3/15/2020 at 12:14 PM, Union Tpke said:

    I don't think you answered one of my questions. How aggressively should runtimes be?

    Well what you should really do is break runtimes out into its components: runtime and dwell. Then try to figure out components: how much of this runtime is holds to time? What about controllable dwells? etc, and then you go ahead and schedule around median runtime, but without those confounding components in the mix. 

  8. 12 hours ago, Trainmaster5 said:

    I will give you the TWU argument but that is not the only reason IMO. We have OPTO at times for parts of the system. No C/R on board. Equipment manufacturers have theoretically had the option to eliminate the T/O for some fifty years or so. The two drawbacks were attributed to safety back then by the TWU (of course), and by the riding public. We had a two person crew and Transit Police officers on every late night train. That level of policing decreased over time. Remove the C/R from the trains might save money. Remove the T/O saves even more money. Next time we experience a blackout and folks are trapped on a train stuck between stations or in a river tube good luck evacuating people to safety with no crew onboard . I can guarantee you that the (MTA) and the State of New York won’t take the hit for being self-insured. The riders will. I don’t know how many posters are aware of the procedure for air travel. Crew takes off and reaches altitude. Suppose the pilot and copilot opened the cabin door and took seats with the passengers for an hour or so before they went back to the cockpit to land the plane. This is what the ultimate driverless train trip would be without a train crew. I don’t think that would go over too well with the riding public in the NYC metro area. Times are changing and I could be wrong but that’s my take. YMMV. Carry on.

    I'm not sure of the advisability of ZPTO without PSDs and the like, but these arguments about blackouts and safety rel. OPTO are relevant to every transit system in the world, yet we're the outlier in still having two person crews. As you point out, this is political and thus not totally responsive to the technical (de)merits of a given configuration, but I think that's a disconnect worth recognizing. 

  9. On 3/15/2020 at 2:01 PM, bobtehpanda said:

    Which neatly sorts out the B Division's northern half. Personally, I think that most of the current subway's systems resiliency problems stem from the northern half, and southern deinterlining is unnecessary.

    Gonna disagree with you here. You're right that Queens and 59 St are trash, but Dekalb and 36 are no walk in the park either! Dekalb is especially troublesome beyond its discrete operational impacts given that it is upstream -- in both directions -- of operationally complex and capacitally restricted areas. For southbound trains, intervals arriving bunched and/or in the wrong order at Coney Island, Brighton Beach or 36 St causes congestion, while northbound variability will throw merges at 34, 59, etc. Those are nontrivial impacts! 

    In my research on this issue, the general pattern that keeps resurfacing is that a chain is only as strong as its weakest link. You can make one part of the system work well, but if all of that capacity is going to run into some mess like Dekalb, you're not going to be able to realize nearly the benefit that you could have if you tried to fluidize the entire line. Now, of course, that one merge probably will become easier to operate because you're going to have fewer cascading impacts running into it, but it's still going to have a nontrivial negative impact on your capabilities. See, for example, Camden Town on LU's Northern. 

  10. 10 hours ago, Trainmaster5 said:

    Again I have to admire the way you think. You might have been taught by my old instructors 😀. The old KISS way of thinking. RR503 did point out the capacity vs the velocity difference so I'll just add my interpretation to that. With a perfect loop configuration there's no need for a crew change and the standard brake tests that must be done as per rule. Train arrives, doors open, passengers exit, enter, doors close, train moves on. Limited dwell time. Typical 2 track station means signal and switch lineup into the station, train dumps air and doors open. Train across the platform closes down while switch and signals align and proceeds. All's well and good if everything works as designed. Let there be a signal or switch problem, especially across the switches, and you have now delayed 2 trains at the terminal. Look back at the recent service advisories and it appears that signal, followed by switch, delays predominate. Two of my instructors were (6) line guys from the old school. It was those gentlemen who instilled the KISS mentality in our heads. When I worked on the work trains and I noticed the diamond crossovers being removed throughout the IRT I asked one of them the reasoning behind it.  You guessed it, KISS. The fewer variables in the equation meant better service in the long run. Just my take. Carry on.

    KISS is generally a good principle by which one may run the railroad, but I do think it’s worth recognizing the ways loops hamper dispatchers’ ability to mitigate service problems. If something happens on the southbound (6) before the PM rush, there’s a near 100% chance that the problem will ricochet back north thanks to the fact that you have little to no terminal recovery time. This in and of itself is a tradeoff — recovery time is an operating cost — but that sort of operating margin really saves the railroad from having to be constantly skipping/holding/pissing off riders. I again don’t think this is an issue that’s clearly best one way or another, just again, tradeoffs....

  11. 20 hours ago, Deucey said:

    How much congestion would it cause to run (G) to Coney Island, and end <F>(F) at Kings Hwy, or run (F)(G) like interlined buses where (G) turns into (F)<F> at either terminal and vice versa?

    If you want to run (F)<F>, you're probably best off extending the yard tracks at Church at 300', reinstalling the full complement of crossovers on the lower level, and running (F)(G) local to Church and <F> express. You can do 10 <F>-KH, 10 <F>-CI,10 (F)-Church and 10 (G)-Church to keep the load on the relay op at Church to a manageable 20tph. Kings Highway can barely handle what it does today, and CI is a joke of a terminal. 

    Just a friendly reminder to everyone that:

    - There is about 25tph of unused capacity in the tunnels between Manhattan and Queens today

    - Up to 10tph of that unused capacity is Forest Hills inefficiency, up to 15 is Astoria and the (R)'s occupancy of space in both 60 and on QB (which can be treated as an extension of 53/63)

    - Some indeterminate figure (if I had to guess, 10-15tph) of that unused capacity is thanks to the extreme complexity of merge/diverge operations on Queens' services.

    The fixes here should be self-evident: fix your terminals, fix your service patterns. We don't need, and cannot justify, more infrastructure until you do those things. 

  12. On 3/9/2020 at 8:04 PM, Jsunflyguy said:

    1) Loops

    Agree with everything here except for this. Loops are good for terminal fluidity, but they wreck your ability to mitigate pipeline issues -- your terminal becomes GIGO. Would add tail tracks and well designed signals entering the terminal to the list as well -- that latter issue plays a role at JC. 

  13. On 3/4/2020 at 5:21 PM, RestrictOnTheHanger said:

    Can anyone confirm if the speed over the switches leaving Whitehall St n/b have had their speed limit increased? Anecdotally (R) and (w) trains seem to go faster leaving the station, even from the middle track

    Yes.

    On 3/3/2020 at 11:16 AM, Union Tpke said:

    Excellent! Is there anything they can do to fix the damage they have done at Continental?

    They could do force and lock, but your switch maint budget would go way up with it moving after every movement through. I personally think the DGTs are bad, but the 80/20 at Forest Hills is in dwell times -- DGTs add 16 seconds to entrance times, while terminal dwells can be anywhere from 45s-120s.

  14. 2 hours ago, Fan Railer said:

    I've seen 67 on a siemens 160 manhattan-bound. Long time ago before they dialed back performance.

    [citation needed] on them dialing performance back. We've had the same signal design standards (=same max acceleration profile) since the mid 1990s. I suspect this was either a really good TO who knew how to play with 2 shots to make them work just right, or a broken speedo

  15. 1 hour ago, Union Tpke said:

    This is a good question re: X. I'll ask around. 

    It's quite disappointing to see that this project somehow didn't get piggybacked onto the oh, idk, 2 years of expressing and weekend shutdowns for the stations work. Costs the agency $$$ and riders time unnecessarily. 

  16. Those of you who don't have the facts to back up your claims about certain types of car equipment having impacts on certain lines shouldn't comment as if you do. It's an unnecessary waste of everybody's time and computer bandwidth. As these charts show, actual (N)(W) runtimes are down vs 2019, even when you limit the analysis to just the PM rush. I don't doubt that the R46s are having 3-10s adverse impacts on dwell times at busier stations and maybe are slowing some express runs slightly, but those impacts seem to be trivial in the face of the general downwards trend in runtimes. 

    PU7u736.png

    B6jUo6g.png

    hXIgXUY.png

  17. 19 hours ago, Trainmaster5 said:

    I'm wondering what you guys would think about the ancient days at DeKalb. Fourth Ave (R) local, Brighton (QT) local, West End (TT) local  and the Sea Beach (N) , Brighton (Q) and the West End  (T) expresses all passing through DeKalb. Back before the 6th Avenue connection went into effect. I don't recall any complaints about merges back then. This was when the (T) had to cross over to reach the Astoria, QB line tracks heading past 57th-7th weekdays. What's really changed as far as merging ? Just asking. Carry on.

    You do realize that the merge delays and capacity losses back then were so bad that the MTA chose to completely rebuild the junction, right? And even then, service did not perform all that well. The 80tph run through in the 1968 pattern got really messy, I'm told, with trains backing up onto the bridge and into Dekalb moreso than even today. 

    All that aside, a lot has changed! Signal mods have made the system less resilient, electronic delay reporting has made numbers fudging harder, and people have higher expectations for service. Just sayin'...

  18. 1 hour ago, Union Tpke said:

    It works for me.

    Yeah, not working for me either.

    To the general discussion: very few issues are, by themselves, conversation-ending propositions when it comes to reroute scenario, and the (3)'s yard placement is especially tractable. Back in the '80s and '90s when these discussions were last had, there existed a much steeper drop off in PM demand to points north on IRT Broadway, which made running (3)s back north from Flatbush expensive relative to loads and contributed to the business case for (3) access to Livonia, This is much less true today, which makes it easier (though of course still a cost) to run the line to Flatbush. 

    Generally, though, there's a reason cost-benefit analyses exist, and it's to resolve question exactly like this one. Upwards of 30% of weekday daytime (2)(3)(5) trains are delayed for more than a minute northbound through Rogers (a stat that's considerably higher during the peaks); on excess runtime expenses alone, this would likely pencil out. 

    Here's some data on hourly loads leaving the core:

    kB9y7PS.png

    vQP0br7.png

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